We can start with simple and complex chemicals that are important to life:
BP. Complex Biological Compounds
We can then address cells, followed by genes, tissues, organs, and systems.
Organisms are addressed in F. Flora and Fauna. Anatomical structure will be a subset (linked to organs). So too will be developmental forms.
B and F are likely by far the hardest classes to classify. In particular, the number of different organisms is simply enormous, and the process of placing each within a logical hierarchy is still a work in progress. But there is an advantage here in developing a new system of classification for we are learning more each day about the proper classification of organisms, and their constituent components.